Jason ChoiProfessor Andrei Shkel

Adam Schofield, Alex Trusov, Ozan Anac

UCI Micro Systems Laboratory Introduction to Gyroscopes Introduction to Resonators

◦ Basic building blocks of tuning fork gyroscopes Gyroscope Characterization Our Approach to Characterizing Devices

◦ Microvision with a Stroboscopic Algorithm Our System Results

Development of MEMS Inertial Sensors◦ Gyroscopes

Tuning Fork Gyroscope Nuclear Magnetic Resonance Gyroscope

Design Modeling Fabrication Characterization

What is a gryoscope?◦ A device that can measure angular motion or

displacement Applications

◦ Aerospace Inertial guidance systems

◦ Automotive Angular rate sensor

◦ Entertainment Pointing devices, Gaming controller

◦ Medical Vestibular prosthesis

http://mems.eng.uci.edu/

http://www.army.mil

http://www.aa1car.com

Coriolis Effect

Drive Oscillation Coriolis Acceleration

http://www.li-bachman.net

Design and Fabricated by Alex Trusov

http://mems.eng.uci.edu/

3 mm

3 mm

Image taken by Alex Trusov

AC Voltage

Ground

DriveOscillation

3 mm

3 mm

Design and Fabricated by Alex Trusov

Thickness of Each Comb = 6 micons

DriveOscillation

Frequency Response◦ Resonant Frequencies

Maximum Amplitudes

Difficulty◦ Small Micro-Scale Devices (mm)◦ Vibration at High Frequency (kHz)

Thousands of vibrations per second◦ Vibration Amplitudes are small (few microns)

Capacitive Sensing◦ Change in the gap between two electrodes

changes the capacitance.◦ Two electrical terminals are used other than the

driving terminals.

Drawbacks◦ Changes in capacitance are small.◦ Indirect method to measure deflection

Calculation of physical deflection is done by theoretical calculations.

Proven Characterization Method◦ Jasmina Casals

Main Idea◦ Video record the vibration of device◦ Extract vibration amplitudes from the extracted

frames of the video

Advantages◦ Optical, Non-Contact Characterization Method◦ Minimal Control Electronics

Standard Image Limited FPS (frames per second) of video camera

Stroboscopic Technique◦ Solution: Stroboscopic Technique N x (Frequency of Strobe) = Frequency of Vibration N = Positive Integer

Example: If Frequency of Vibration = 30KHz One solution: Frequency of Strobe = 30Hz, N = 1000

Picture by Alex Trusov

0 10 20 30 40 50 60 70 80 90 1000

0.2

0.4

0.6

0.8

1

1.2

Time

Am

plitu

de

Device OscillationStrobe LEDIllumination Point

Computer• Image Pro - Capture Image - Image Processing• MATLAB - Data Processing - Sinusoidal Fit

AC/DC Source

StrobeLight

CCDCamera

MEMSDevice

MicroscopeTrigger Signal

AC/DC Source

CCD Camera

Microscope

MEMS Device StroboscopeComputer

Trigger Source

MEMS Device

Yellow: non-moving part of device Pink: moving part of device

0 50 100 150 200 250 300

38

40

42

44

46

48

50

52

54

Frames

Dis

tanc

e (m

icro

ns)

distance in each frame6.268 X sin (x / 9.507 - 0.1103) + 46.38

0 50 100 150 200 250 300

4

6

8

10

12

14

16

18

Frames (29.97Hz)

Pos

ition

(m

icro

ns)

rdata vs. x3.432 X sin(0.1424x + 3.953) + 10.88

10 20 30 40 50 60

12

14

16

18

20

22

24

Frames

Dis

tanc

e (m

icro

ns)

distance per frame5.765 X sin(x / 4.186 - 2.184) + 17.57

One Example

Freq. of Motion◦ 2460Hz

Freq. of Strobe◦ 55.909Hz◦ N = 44

Amp. of Motion◦ 5.77 ± 0.05 micron

10 20 30 40 50 60

12

14

16

18

20

22

24

Frames

Dis

tanc

e (m

icro

ns)

distance per frame5.765 X sin(x / 4.186 - 2.184) + 17.57

Successful Final Product◦ Measure amplitudes of vibration

Image Pro Macro Programming MATLAB Data Processing

◦ Amplitude Precision (standard deviation of nonmoving object)

± 0.05 microns

◦ Successful Upgrade in Camera Better Images

◦ Optional LabVIEW VI to automatically actuate device and set strobe frequency

Verify Accuracy of Amplitudes with Electrical Capacitance Measurements

Characterize Devices

Continue Project to Characterize 3-D Movement

Said Shokair Professor Andrei Shkel Jasmina Casals Adam Schofield Alex Trusov Ozan Anac IM-SURE Fellows

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